Vacancy distribution in synthetic spinels of the series Fe304–γ-Fe2O3

Abstract

Abstract The original samples of the magnetite series Fe3O4–γFe2O3 of G.Hägg have been investigated with x-ray diffraction and Mössbauer spectroscopy. X-ray diffraction studies showed that the intensities of the superstructure lines increase with increasing deviation from the stoichiometric ratio. The patterns of all samples exhibited a cubic-primitive lattice. Tetragonal symmetry was not observed. Mössbauer absorption spectra gave evidence for vacancy distributions over tetrahedral as well as octahedral iron sites of magnetite. Broadening of the octahedral iron lines indicated that the relaxation times of the hopping electrons at constant temperature increases as the deviation from the stoichiometric ratio increases.